/*
* JBoss, Home of Professional Open Source.
* Copyright 2008, Red Hat Middleware LLC, and individual contributors
* as indicated by the @author tags. See the copyright.txt file in the
* distribution for a full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.jboss.proxy;
import java.io.IOException;
import java.io.ObjectInput;
import java.util.Collections;
import java.util.Map;
import java.util.WeakHashMap;
import org.jboss.ha.framework.interfaces.FamilyClusterInfo;
import org.jboss.invocation.Invocation;
import org.jboss.invocation.InvokerProxyHA;
import org.jboss.invocation.ServiceUnavailableException;
import org.jboss.logging.Logger;
import org.jboss.tm.TransactionPropagationContextFactory;
import org.jboss.tm.TransactionPropagationContextUtil;
/**
* Parent transaction sticky interceptor that encapsulates sticky target map
* and exposes operations on this map.
*
* @author <a href="mailto:galder.zamarreno@jboss.com">Galder Zamarreno</a>
*/
public abstract class AbstractTransactionStickyInterceptor extends Interceptor
{
private static final Map txStickyTargets = Collections.synchronizedMap(new WeakHashMap());
private FamilyClusterInfo familyClusterInfo;
protected final Logger log = Logger.getLogger(getClass());
protected static boolean trace = false;
public AbstractTransactionStickyInterceptor()
{
trace = log.isTraceEnabled();
}
/**
* Called at the beginning of the invocation to check whether the current tpc
* is already present in the tx sticky target. If it is, get the chosen
* target associated to it and add it to the invocation transient payload so
* that the load balance policy can choose the right target as long as the
* target is available in the cluster family. Otherwise, invocation needs to
* be halted because a previous invocation within the transaction succeeded
* (tx sticky target was set), so we can't failover to a different node.
*
* @param invocation Invocation object where transaction sticky will be set
* if present.
*/
protected void putIfExistsTransactionTarget(Invocation invocation) throws Exception
{
Object tpc = getTransactionPropagationContext();
if (tpc != null)
{
if (trace)
{
log.trace("In the proxy, transaction propagation context (tpc) is " + tpc);
log.trace("Contains key returns " + txStickyTargets.containsKey(tpc));
}
Object stickyTarget = txStickyTargets.get(tpc);
if (stickyTarget != null)
{
if (getFamilyClusterInfo(invocation).getTargets().contains(stickyTarget))
{
if (trace)
{
log.trace("Put transaction bound target into transient payload: " + stickyTarget);
}
invocation.getTransientPayload().put("TX_STICKY_TARGET", stickyTarget);
}
else
{
throw new ServiceUnavailableException("Transaction sticky target is no longer available, so invocation needs to be halted");
}
}
}
}
/**
* Method called to remember the sticky target associated with a transaction
* context.
*
* @param invocation Invocation object from which the TX_STICKY_TARGET
* transient value comes from.
* @param tpc Transaction propagation context.
*/
protected void rememberTransactionTarget(Invocation invocation, Object tpc)
{
if (trace)
{
log.trace("After reaching the server, transaction propagation context (tpc) is " + tpc);
}
Object stickyTarget = invocation.getTransientValue("TX_STICKY_TARGET");
if (stickyTarget != null)
{
if (trace)
{
log.trace("Remember transaction bound target [" + stickyTarget + "] for tpc " + tpc);
}
txStickyTargets.put(tpc, stickyTarget);
/* Put it in invoker proxy txFailoverAuthorizations to avoid failover being
* allowed if the 1st EJB invocation within user trasnsaction fails with
* GenericClusteringException.COMPLETED_NO */
InvokerProxyHA proxy = (InvokerProxyHA)invocation.getInvocationContext().getInvoker();
proxy.forbidTransactionFailover(tpc);
}
}
@Override
public void readExternal(ObjectInput in) throws IOException, ClassNotFoundException
{
super.readExternal(in);
trace = log.isTraceEnabled();
}
protected Object getTransactionPropagationContext()
{
TransactionPropagationContextFactory tpcFactory = TransactionPropagationContextUtil.getTPCFactoryClientSide();
if (trace)
{
log.trace("Using tpc factory " + tpcFactory);
}
return (tpcFactory == null) ? null : tpcFactory.getTransactionPropagationContext();
}
protected synchronized FamilyClusterInfo getFamilyClusterInfo(Invocation invocation) throws Exception
{
if (familyClusterInfo == null)
{
InvokerProxyHA proxy = (InvokerProxyHA)invocation.getInvocationContext().getInvoker();
familyClusterInfo = proxy.getFamilyClusterInfo();
}
return familyClusterInfo;
}
}